With over 80 million inefficient heating & cooling (HC) systems still installed across Europe motivating consumers to replace those units with more efficient, greener alternatives will be key for a decarbonised Energy Union fuelled by renewable energy. REPLACE therefore aims to improve coordination in local networks to implement replacement campaigns in ten target regions by means of action plans fortified with policy and business-related improvements. Based on lessons learnt from previous projects and sound on-the-ground research on stakeholders’ mind-sets, local working groups (LWGs) will connect all key actors in each region – local governments, consumer associations, developers, energy utilities and professional associations – to steer the direction of a wide range of replacement activities. For the first time, REPLACE will explicitly unite intermediaries, such as chimney sweepers or installers, who have constant access to consumers, and policy makers to develop common activities with maximum impact. REPLACE supports the LWGs by providing a communication framework and a rich toolbox of online and offline actions targeted to the needs of all relevant stakeholders. The “REPLACE Your Heating System Calculator” will be central in raising consumers’ and investors’ awareness of the monetary and wider benefits of HC replacements and develop real momentum towards collective actions. By making all materials openly accessible and highlighting success stories the uptake of activities can be multiplied beyond target regions. In addition, all activities will be firmly established within local policy programmes to ensure that the overall impact of REPLACE is sustainable and the networks forged during the action will continue beyond project life. Together with a dedicated focus on capacity-building measures and knowledge transfer REPLACE identifies and merges all elements necessary to successfully make heating and cooling for European consumers efficient and climate-friendly.